Answer:
See explaination and attachment.
Explanation:
Navier-Stokes equation is to momentum what the continuity equation is to conservation of mass. It simply enforces F=ma in an Eulerian frame.
The starting point of the Navier-Stokes equations is the equilibrium equation.
The first key step is to partition the stress in the equations into hydrostatic (pressure) and deviatoric constituents.
The second step is to relate the deviatoric stress to viscosity in the fluid.
The final step is to impose any special cases of interest, usually incompressibility.
Please kindly check attachment for step by step solution.
Answer:
a) the amount of energy produced in kJ/K is 0.73145 kJ/K
b) the amount of energy produced in kJ/K is 0.68975 kJ/K
The value for entropy production obtained using constant specific heats is approximately 6% higher than the value obtained when accounting explicitly for the variation in specific heats.
Explanation:
Draw the T-s diagram.
a)
= 0.939 kJ/kg.K , m = 5 kg , T₂ = 520 K , T₁ = 280
R = [8.314 kJ / 44.01 kg.K] , P₂ = 20 bar , P₁ = 2 bar
Δs = ![m[c_p ln(\frac{T_2}{T_1}) - Rln(\frac{P_2}{P_1})]](https://tex.z-dn.net/?f=m%5Bc_p%20ln%28%5Cfrac%7BT_2%7D%7BT_1%7D%29%20-%20Rln%28%5Cfrac%7BP_2%7D%7BP_1%7D%29%5D)
Substitute all parameters in the equation
Δs = ![5[(0.939) ln(\frac{520}{280}) - (\frac{8.314}{44.01})ln(\frac{20}{2})]](https://tex.z-dn.net/?f=5%5B%280.939%29%20ln%28%5Cfrac%7B520%7D%7B280%7D%29%20-%20%28%5Cfrac%7B8.314%7D%7B44.01%7D%29ln%28%5Cfrac%7B20%7D%7B2%7D%29%5D)
Δs = 5 kg × 0.14629 kJ/kg.K
= 0.73145 kJ/K
b)
Δs = ![m[\frac{s^0(T_2) - s^0(T_1)}{M} - Rln(\frac{P_2}{P_1})]](https://tex.z-dn.net/?f=m%5B%5Cfrac%7Bs%5E0%28T_2%29%20-%20s%5E0%28T_1%29%7D%7BM%7D%20-%20Rln%28%5Cfrac%7BP_2%7D%7BP_1%7D%29%5D)
Where T₁ = 280 K , s°(T₁) = 211.376 kJ/kmol.K
T₂ = 520 K , s°(T₂) = 236.575 kJ/kmol.K
R = [8.314 kJ / 44.01 kg.K] , M = 44.01 kg.K , P₂ = 20 bar , P₁ = 2 bar
Δs = ![5[\frac{236.575 - 211.376}{44.01} - (\frac{8.314}{44.01})ln(\frac{20}{2})]](https://tex.z-dn.net/?f=5%5B%5Cfrac%7B236.575%20-%20211.376%7D%7B44.01%7D%20-%20%28%5Cfrac%7B8.314%7D%7B44.01%7D%29ln%28%5Cfrac%7B20%7D%7B2%7D%29%5D)
= 5 kg (0.13795 kJ/kg.K)
= 0.68975 kJ/K
The value for entropy production obtained using constant specific heats is approximately 6% higher than the value obtained when accounting explicitly for the variation in specific heats.
In Menlo Park, California, Hwan Rhee is debating whether to launch ChargeAll, a software firm that will create full-room wireless chargers for any kind of mobile electronic device.
In Menlo Park, California, Hwan Rhee is debating whether to launch ChargeAll, a software firm that will create full-room wireless chargers for any kind of mobile electronic device. In order to examine the financial information for a startup loan that would pay for the components and product manufacture, Hwan is using an Excel worksheet. He requests your assistance in fixing mistakes and performing financial computations in the worksheet.
Visit the worksheet for loan analysis. Hwan requests that you fix the mistakes in the worksheet before he can compute the principal and interest payments on the loan.
To know more about software click here:
brainly.com/question/985406
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To indentify the machines in our school that have a pulley system as the drive mechanism and the advantages of Pulley system is given below
Explanation:
1.A pulley is a wheel with a groove along its edge, that holds a rope or cable. ... When pulleys are used together in this way, they reduce the amount of force needed to lift a load. A crane uses pulleys to help it lift heavy loads. Pulleys are one of the six simple machines.
2.Examples of pulleys include:
- Elevators use multiple pulleys in order to function.
- A cargo lift system that allows for items to be hoisted to higher floors is a pulley system.
- Wells use the pulley system to hoist the bucket out of the well.
- Many types of exercise equipment use pulleys in order to function.
3.Using multiple pulleys decreases the amount of force necessary to move an object by increasing the amount of rope used to raise the object. The mechanical advantage (MA) of a pulley system is equal to the number of ropes supporting the movable load.
4.To calculate the mechanical advantage of a pulley you simply have to count the number of rope sections that support whatever object you are lifting (not counting the rope that is attached to the effort). For example, in a one pulley system the MA is 1. ... Therefore your mechanical advantage would be 2 (600/300).
5.The movable pulley is used to reduce the amount of input force to lift a load. The most popular system that uses this pulley would be a well. Unlike the fixed pulley, the movable pulley is attached to the load, and is lifted by pulling up on the rope, making it twice as easier to lift a heavy object.
6.The main benefit of the pulley is that it can actually reduce the amount of force which is required to lift heavy objects and redistributes the direction of the force to lift heavy objects
